Stack damper and control assembly for furnaces



Sept. 20, 1966 P. R. HOLTZMAN ETAL STACK DAMPER AND CONTROL ASSEMBLY FOR FURNACES Filed Aug. 5, 1965 FIG. 1.

FIG. 2. E..

5 Sheets-Sheet 1 FIG. 4.

INVENTORS PAUL R. HOLTZMAN ALLEN B. HOLTZMAN BY M ATTORNEYS P 20, 1966 P. R. HOLTZMAN ETAL 3,273,625

STACK DAMPER AND CONTROL ASSEMBLY FOR FURNACES Filed Aug. 3, 1965 3 Sheets-Sheet 2 4 4 4 5 I 4 6/ :Z? 4 l 5 MW @107. 4 u a 2 7 2 4 4 4 7 1 9 h 4 9 T 4 l1 M -1 6 5 2 5. l V N 3 w s I I r/r/Y////////f/Aj G mc o GG 0\ 4 '1. 4

m 7 A. w 2 5 IIIlIlIIIJ lllllllll J 1 8 .II. .2 n ll 8 |rl G 2 it. H -1 INVENTORS PAUL R. HOLTZMAN ALLEN B. HOLTZMAN FIG.6.

ATTORNEYS Mi a/M p 20, 1966 P. R. HOLTZMAN ETAL 3,273,625

STACK DAMPER AND CONTROL ASSEMBLY FOR FURNACES Filed 1965 5 Sheets-Sheet 3 F AME 0 TECTOR THERMOSW BURNER CONTROL IGNITIoN TRANSFORMER l INPUT 60 GROUND GROUND j 65 69 66 BURNER MOTOR FIG. ll. 64

OIL DELAY 49 72 VALVE 73 F *1: T T

L. DAMPER 5? 54 MOTOR 56 I I 7 70 L. T l

67 DAMPER CONTROL UNIT 5 32 FIG 7.

E I I INVENTORS P, PAUL R. HOLTZ MAN ALLEN s. HOLTZMAN BY gnaw/1,74 w ATTOR Y5 United States Patent Office 3,273,625 Patented Sept. 20, 1966 3,273,625 STACK DAR HER AND CONTROL ASSEMBLY FOR FURNACES Paul R. Holtzrnan, 200 S. Railroad St., and Allen B. Holtzman, Rte. 3, both of Myerstown, Pa. Filed Aug. 3, 1965. Ser. No. 476,954 4 Claims. (Cl. 15828) This invention is a stack damper and control assembly for furnaces, an object of which is to shut off all drafts normally circulated through the furnace, when the latter is not operative.

Another object is to provide a stack damper control in circuit with a standard furnace control unit, for effecting opening of the damper synchronously with the operation of the furnace, the damper automatically closing when the furnace is not operating; either due to thermostatic control or a malfunction thereof.

A further object is to provide a stack damper control for furnaces wherein the damper is operated by a low cost, high torque motor such as the Enercon 45 unidirectional double oscillator motor that achieves low speed rotary motion of the damper connected thereto, without the use of gears, the motor further effecting positive stopping of the damper for fully open or fully closed position, without override and accurately repeats successive cycles of operation.

A still further object is to provide a stack damper and control assembly for furnaces including an air vent in the damper housing wall for the admission of air when the damper is closed, to cool the chimney when the furnace is not operating and draw off excessive heat around the furnace area.

A still further object of the present invention is to provide a stack damper and control assembly of the character described which is applicable to hot Water, steam and hot air furnace installations which is capable of effecting a fuel saving of between 25% and 40%.

Other objects of the invention will be manifest from the following description of the present preferred form of the invention, taken in connection with the accompanying drawings, wherein:

FIG. 1 is a side elevational view of a stack damper and control assembly constructed in accordance with the present invention, illustrating its application;

FIG. 2 is an end elevational view of the same, portions thereof being broken away to disclose details;

FIG. 3 is a horizontal sectional view taken along the lines 33 of FIG. 1, looking in the direction of the arrows, parts of the damper control being broken away to disclose details of construction;

FIG. 4 is a vertical sectional view taken along the lines 44 of FIG. 3, looking in the direction of the arrows;

FIG. 5 is a sectional view taken along the lines 55 of FIG. 3, looking in the direction of the arrows, illustrating the manner of operating shaft, position;

FIG. 6 is a view similar to FIG. 5, showing the damper in open position;

FIG. 7 is a sectional view taken along the lines 7-7 of FIG. 3, looking in the direction of the arrows;

FIGS. 8, 9 and are identical views taken along the lines 8-8; 9-9; and 10-10 of FIG. 3, looking in the directions of the arrows, showing the manner of mounting the cam-operating elements of the damper control on the damper-operating shaft and illustrating the operation of micro-switches for carrying out the objects of the present invention; and

FIG. 11 is a diagrammatical view of the electrical circuitry connecting the damper control to the furnace burner control unit.

the damper being shown in closed mounting the damper on the damper- For purposes of illustrating the application of the pres. ent invention there is fragmentarily shown, in FIGS. 1 and 2, a furnace equipped with a stack 21, between which is interposed the stack damper and control assembly constructed in accordance with the present invention. This assembly includes a damper unit 22, to one side of which is connected an air vent control unit 23, and to the other side of which is connected a damper control unit 24.

Damper unit 22 includes a damper-carrying cylinder 25, joined at its lower end to furnace 20 and at its upper end to stack 21. As shown in FIGS. 3 to 6, a disk-shaped damper 26 is diametrically mounted on an operating shaft 27 to which it is detachably secured, as indicated at 28. The outer periphery of damper 26 lies in close proximity to the inner periphery of cylinder when the damper is in closed position. Cylinder 25 is provided with a series of horizontally aligned air ports 29 lying in a plane above shaft 27 for purposes which will be hereinafter more fully set out.

Both ends of shaft 27 extend through and beyond the outer periphery of cylinder 25, one end of the shaft projecting through and beyond air vent control unit 23, the terminals being journaled in suitable bearings 30 and 31.

Air vent control unit 23 includes side walls 32, an end wall 33, top wall 34 and bottom wall 35. As shown to advantage in FIGS. 2 to 6, end wall 33 is provided with vertically spaced air openings 36 lying in a vertical plane with shaft 27. Bearing 3t), in which one end of shaft 27 is journaled is fixedly secured to end wall 33. In conjunction with end Wall 33, there is provided a rotatable disk 37 centrally mounted on shaft 27, the disk being provided with space-d air openings 33 which are aligned with air openings 36 of end wall 33, when damper 26 is in closed position. Disk 37 is fixed to a spacer washer 39 interposed between the disk and the damper-carrying cylinder 25, the washer being fixed to shaft 27 to effect synchronous rotation of disk 37 with shaft 27 and damper 26 secured thereto.

As shown to advantage in FIGS. 5 and 6, air openings 36 and 38 are aligned when damper 26 is in closed position for admission of air therethrough and through air ports 29 to the interior of damper unit 22 at a point above damper 26. When damper 26 is rotated to the open position illustrated in FIG. 6, air openings 38 are rotated to a point of non-alignment with air openings 36, thereby shutting off the admission of air through ports 29 to the interior of damper-carrying cylinder 25.

Damper control unit 24 is of generally box-like construction and includes side walls 40 and 41, the inner terminal of which walls are fixed to damper-carrying cylinder 25. An end wall is indicated at 42 and a top at 43. An electrical connection insulating board is fixed to side wall 41 and is spaced therefrom by members 45'. Damper control unit 24 further includes spaced interior walls 46 and 47. That portion of shaft 27 beyond bearing 31 extends through an opening in wall 46 to a point adjacent wall 47 where it is connected to a drive shaft 48 of a motor 49, the motor shaft passing through an opening in wall 47. Damper motor 49 is fixed to wall 47 by suitable motor mounts 50. Mounted on walls 40* and 41 of damper control unit 24 are racket supports 51, 52 and 53 on which are mounted micro-switches 54, 55 and 56 respectively, the actuating arms of which switches extend below and in spaced relation to operating shaft 27. It is further within the contemplation of the present invention to provide, in conjunction with micro-switches 54, 55 and 56, actuating means therefor, in the form of cams, designated 57, 58 and 59 which are mounted on operating shaft 27 in superjacent relationship to the actuating arms of micro-switches 54, 55 and 56 respectively. The microswitches, in turn, selectively open and close electrical circuits for synchronizing the operation of the damper with "-3 the operation of the furnace. The position and operation of the cams and micro-switches controlled thereby are shown to advantage in FIGS. 8, 9 and 10.

Damper motor 49 is preferably an Enercon 45 unidirectional double oscillator motor which requires no gears and effects positive stop without override, thereby effecting full opening and full closing during successive phases of the operational cycle. This motor has also proven to accurately repeat the cycle of operation throughout successive cycles.

In FIG. 11 there is illustrated a diagrammatic electrical layout for connecting the damper and control assembly of the present invention to the electrical system of a furnace. In this connection there is indicated at '59, a standard burner control such as type 663.1 manufactured by White-Rodgers Co., the control being connected to a suitable electrical source and including a thermostat 69, a flame detector 61 and an ignition transformer 62. FIG. 11 illustrates the present invention applied to an oil burner, the burner motor being indicated at 63 and an oil delay valve at 64. When thermostat 69 calls for heat, damper motor 49 is actuated through electrical line 65 extending from the burner control to one side of microswitch 56 and from the micro-switch to the motor, through line 67. This effects rotation of damper 26 through a 90 arc to the open position. Where the heat demand ceases, the damper motor drives the shaft another 90 by energization, through line 66 to close the damper. Ground line is indicated at 68. After the damper is partially for fully open, depending upon the individual installation, burner motor 63 is activated by burner control 59 upon closing of switch 55, to effect operation of the motor through lines 69 and 70. Ground line is indicated at 71. Ignition is also effected when burner motor 63 starts but combustion cannot take place until the damper is in fully open position, at which time the delay valve '64 is energized upon closing of micro-switch 54 by operation of cam 57. The circuit to the oil delay valve iscompleted through lines '72 and "73, the latter being connected to burner motor 63. A ground line is indicated at 74. When the demand for heat is satisfied, burner control 59 deactivates burner motor 63 and activates damper motor 49, interrupting the ignition circuit and closing oil delay valve 64. The damper motor 49 operates until the damper is in fully closed position, at which time it becomes inoperative. In the event of current and/ or flame failure while the damper is in an open position, the same operation as set out above takes place to effect closing of the damper in a normal manner.

When damper 26 is in a closed position, air vent control unit 23 permits the admission of air through openings 36, 38 and ports 29 to the damper-carrying cylinder 25 in order to lower the temperature of the chimney when the burner is not operating. The hazard of a fire in the chimney is thereby reduced. In homes with summer and winter hook-up, this arrangement further tends to draw off excess heat around the furnace area. Air vent control unit 23 is automatically rendered inoperative upon opening of damper 26.

The damper and control assembly of the present invention is applicable to hot water, steam, hot air and gas furnace installations and it has been found in actual practice that the present damper and control assembly is capable of effecting a saving of 25% to 40% in fuel, depending upon the efficiency of the furnace unit itself.

While there has been herein shown and described, a preferred embodiment of the present invention, it is nevertheless to be understood that various changes may be made therein, without departing from the spirit and scope of the appended claims.

v electrical switches proximate said We claim:

1. A stack damper and control assembly for a furnace equipped with a stack, a burner motor and burner motor control unit; the assembly including a damper unit interposed between the furnace and stack, the damper unit comprising a damper cylinder, a disk-shaped damper within said cylinder, at rectilinear operating shaft mounted in said cylinder, said damper being diametrically fixed to said operating shaft, and a damper control unit operatively connected to said damper unit, the damper control unit including unidirectional, low speed, high torque motor means in direct engagement with the operating shaft of said damper unit, switch means on said damper control unit in circuit with the burner control unit and the burner motor, and switch-actuating means mounted on said operating shaft and rotatable therewith, for operating said switch means at predetermined intervals.

2. The stack damper and control assembly of claim 1 wherein said damper cylinder is provided with air ports and the control assembly further includes an air vent control unit connected to said damper assembly at the locus of the air ports, the air vent control unit including a housing into which said operating shaft extends, the housing including side, top, bottom and end walls, said end wall being provided with spaced air openings, an inner wall mounted on said operating shaft proximate the end wall of said housing, the inner wall being provided with air openings for alternate alignment and non-alignment with the air openings of the end wall of said housing upon rotation of the operating shaft.

3. The stack damper and control assembly of claim 1 wherein said motor is a Enercon 45 unidirectional double oscillator electric motor.

4. A stack damper and control assembly for an oil furnace equipped with a burner motor, a burner motor control unit and an oil delay valve; the assembly including a damper unit interposed between the furnace and stack, the damper unit comprising a damper cylinder, a diskshaped damper within said cylinder, a rectilinear operating shaft extending through said cylinder and being rotatable with respect thereto, said shaft being diametrically fixed to said damper for effecting opening and closing thereof upon rotation of the shaft, a damper control unit operatively connected to said damper unit, the damper unit including a unidirectional low speed, high torque motor in direct driving engagement with one terminal of said operating shaft, cams fixed to said operating shaft, cams and adapted to be actuated thereby upon rotation of said operating shaft, said switches being in circuit with the burner motor, damper motor and oil delay valve and an air control unit connected to said damper unit, said air vent control unit including a housing into which said operating shaft extends, the housing comprising side, top, bottom and end walls, said end wall being provided with spaced air openings, an inner wall mounted on said operating shaft proximate the end wall of said housing, the inner wall being provided with air openings for alternate alignment and non-alignment with the air openings of the end wall of said housing upon rotation of the operating shaft.

References Cited by the Examiner UNITED STATES PATENTS 1,665,599 4/1928 McCulloch 126-292 2,155,642 4/1939 Dewey.

2,633,299 3/1953 Brown 158-28 3,025,446 3/1962 Lefiler 236-1 JAMES W. WESTHAVER, Primary Examiner. 

1. A STACK DAMPER AND CONTROL ASSEMBLY FOR A FURNACE EQUIPPED WITH A STACK, A BURNER MOTOR AND BURNER MOTOR CONTROL UNIT; THE ASSEMBLY INCLUDING A DAMPER UNIT INTERPOSED BETWEEN THE FURNACE AND STACK, THE DAMPER UNIT COMPRISING A DAMPER CYLINDER, A DISK-SHAPED DAMPER WITHIN SAID CYLINDER, A RECTILINEAR OPERATING SHAFT MOUNTED IN SAID CYLINDER, SAID DAMPER BEING DIAMETRICALLY FIXED TO SAID OPERATING SHAFT, AND A DAMPER CONTROL UNIT OPERATIVELY CONNECTED TO SAID DAMPER UNIT, THE DAMPER CONTROL UNIT INCLUDING UNIDIRECTIONAL, LOW SPEED, HIGH TORQUE MOTOR MEANS IN DIRECT ENGAGEMENT WITH THE OPERATING SHAFT OF SAID DAMPER UNIT, SWITCH MEANS ON SAID DAMPER CONTROL UNIT IN CIRCUIT WITH THE BURNER CONTROL UNIT AND THE BURNER MOTOR, AND SWITCH-ACTUATING MEANS MOUNTED ON SAID OPERATING SHAFT AND ROTATABLE THEREWITH, FOR OPERATING SAID SWITCH MEANS AT PREDETERMINED INTERVALS. 